Re: [PATCH] perf/x86: Apply more accurate check on hypervisor platform

[Peter Zijlstra]

On Thu, Jul 25, 2019 at 10:39:26AM +0800, Zhenzhong Duan wrote:
> check_msr is used to fix a bug report in guest where KVM doesn't support
> LBR MSR and cause #GP.
> 
> The msr check is bypassed on real HW to workaround a false failure,
> see commit d0e1a507bdc7 ("perf/x86/intel: Disable check_msr for real HW")
> 
> When running a guest with CONFIG_HYPERVISOR_GUEST not set or "nopv"
> enabled, current check isn't enough and #GP could trigger.
> 
> Signed-off-by: Zhenzhong Duan <zhenzhong.duan@xxxxxxxxxx>
> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
> Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
> Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
> Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> Cc: Borislav Petkov <bp@xxxxxxxxx>
> Cc: Juergen Gross <jgross@xxxxxxxx>
> Cc: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>

Thanks!